Pharmacological and clinical research of minoxidil in hair loss treatment

Minoxidil can promote hair growth by a variety of ways. Topical minoxidil system can absorb very little. There is sufficient clinical trials confirmed that minoxidil has good effects on androgenetic alopecia and alopecia areata. Large-scale clinical trials have confirmed that topical minoxidil hair loss treatment is safe. Minoxidil is a commonly used and effective drug for hair loss treatment. It is not very clear for its pharmacological effects and the role of target cells. But in recent years, studies have shown that minoxidil may promote hair growth through a variety of ways.

The normal hair follicle epithelial cells are cultured in different concentrations of minoxidil solution. In the micromolar concentration, minoxidil may stimulate hair follicle epithelial cell proliferation. Minoxidil sulfate is the active metabolite stimulates hair growth, while the sulfuric acid transferase activity in the hair follicle in the epidermis and dermis. Cysteine ​​synthetic hair keratin experiment confirmed that rat tentacles of hair follicles in vitro histological culture and the s tag: minoxidil sulfate are germinal. In vitro experiments showed that the role of minoxidil sulfate minoxidil l4, the inclusion of sulfotransferase inhibitors or sulfuric acid scavenger to inhibit germinal role of minoxidil, but the sulfuric acid metabolites had no effect. Animal experiments have shown that minoxidil can increase the dermal papilla, hair matrix, outer root sheath and hair around the number of fiber cells. Thus it extends the hair growth long term and promotes vellus hair to terminal hair conversion.

Network of blood vessels provide nutrition for hair growth relies on the dermal papilla, vascular endothelial growth factor mRNA expression in different growth period of vascular endothelial growth factor mRNA is strongly expressed in dermal papilla cells, but in the back catagen and telogen, the hair growth cycle of expression less. The experiments showed that biotin dose-dependent increase in the expression of vascular endothelial growth factor mRNA and protein, thereby promoting the formation of dermal papilla blood vessels, increasing the local blood supply.

Potassium channel opening is an important step in regulating hair growth, an animal model of in vivo and in vitro experiments have shown that minoxidil, a potassium channel activator, increase the potassium ion permeability to prevent calcium inflow cells, resulting in cells free calcium concentration decreased, while calcium, epidermal growth factor inhibits hair growth. Minoxidil equally effective for female androgenetic alopecia.

Mechanism of minoxidil hair loss treatment is unknown. The present study suggests that minoxidil can directly stimulate the hair follicle epithelial cell proliferation and differentiation. It will promote angiogenesis, increase local blood flow and open potassium channels. It can make hair follicles from the telogen to the growing season transformation. Topical minoxidil system absorption is minimal. The shorter the hair loss period is, the smaller the area is, and then the better the prognosis will be. The efficacy of high concentrations is better than low concentrations. But it will cause local adverse reactions.

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